The present invention relates to a plug body for a plastic container receiving liquids such as blood.
In the past, a container is filled with liquid such as blood, a lip portion of the container is then sealed by a plastic cap so that the container is sterilized, a rubber plug is fitted in or placed thereon, and a thermal shrinking overlap portion is further formed thereon. This construction is disadvantageous in that the rubber plug is not subjected to process of sterilization. That is, if sterilization is effected with the rubber plug attached to the container, cooling water enters between the plastic cap and the rubber plug during the sterilization process, which is bad for the health, and in addition, the rubber plug itself proceeds with deterioration under the influence of water at high temperature. Even if a fit is provided between the rubber plug and the plastic cap, there disadvantageously arises a liquid leakage from a boundary between the rubber plug and the plastic cap when a needle is inserted or removed.